apache 如何使用带有 URL 参数的 SetEnv
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How to use SetEnv with a URL parameter
提问by l0b0
I'm trying to implement language switching in .htaccess, and the only thing left now is to handle clients which don't support cookies. To do that, I must set prefer-languagewhen the user clicks a link with a languageparameter.
我正在尝试在 .htaccess 中实现语言切换，现在唯一剩下的就是处理不支持 cookie 的客户端。为此，我必须设置prefer-language用户单击带有language参数的链接的时间。
RewriteEngine On
RewriteBase /
RewriteCond %{QUERY_STRING} (?:^|&)language=(en|fr|no)
RewriteRule ^(.*)$ ? [cookie=language:%1:.example.com,env=language:%1,R]
SetEnv prefer-language $language
The problem is with the last line - The value is always set to empty. It works if I hardcode it, but not if I try to refer to a variable. Is there some special syntax to refer to environment variables in this context, or is there some other way to set prefer-language?
问题出在最后一行 - 该值始终设置为空。如果我对它进行硬编码，它会起作用，但如果我尝试引用一个变量，它就会起作用。在此上下文中是否有一些特殊的语法来引用环境变量，或者是否有其他方法可以设置prefer-language？
Edit: Cross-posted to Apache users list.
编辑：交叉发布到Apache 用户列表。
回答by Gumbo
You can set environment variables with mod_rewrite as well. Actually, you already did that (see env/Eflag).
您也可以使用 mod_rewrite 设置环境变量。实际上，您已经这样做了（请参阅env/ Eflag）。
I can't test it with mod_negotiation myself, but the following should work and set the prefer-language:
我自己不能用 mod_negotiation 测试它，但以下应该可以工作并设置prefer-language：
RewriteCond %{QUERY_STRING} ^((?:[^&]&)*)language=(en|fr|no)&?([^&].*)?$
RewriteRule ^ %{REQUEST_URI}?%1%3 [L,CO=language:%2,R]
RewriteCond %{HTTP_COOKIE} (^|[,\s])language=([^\s,;]+)
RewriteRule ^ - [L,E=prefer-language:%2]
SetEnvIf REDIRECT_prefer-language (.+) prefer-language=
But it would be far easier if you put the language identifier into the URL path like /en/…:
但是，如果您将语言标识符放入 URL 路径中，则会容易得多，例如/en/…：
SetEnvIf Request_URI ^/(en|fr|no)/ prefer-language=
SetEnvIf REDIRECT_prefer-language (.+) prefer-language=
I don't know if you need the additional/second SetEnvIfvariable.
我不知道您是否需要附加/第二个SetEnvIf变量。
回答by l0b0
Looks like there's no support for variables in SetEnv, but here's a working configuration if someone else is trying to do the same. It's a simpler kind of language selection, since it just copies the languageparameter from the referer to the current URL if it's not changed:
看起来 SetEnv 中不支持变量，但如果其他人试图做同样的事情，这里有一个工作配置。这是一种更简单的语言选择，因为它只是language将引用中的参数复制到当前 URL（如果它没有更改）：
RewriteEngine On
RewriteBase /
# Keep the language parameter if specified in the last URL
RewriteCond %{HTTP_REFERER} ^(?:.*[&?])?language=(en|fr|no).*$
RewriteCond %{QUERY_STRING} !^(?:.*&)?language=(en|fr|no).*$
RewriteRule ^(.*)$ ?language=%1 [redirect=permanent]
# Set the language from the URL parameter
RewriteCond %{QUERY_STRING} ^(?:.*&)?language=(en|fr|no).*$
RewriteRule ^ - [env=prefer-language:%1]
# Cache only when the language parameter is set
<IfDefine !prefer-language>
Header set Vary *
</IfDefine>
